Permutation-lock dial.



W. T. BENHAM. PERMUTATION LOGK DIAL. APPLICATION IILED JAN. 2a, 1913.

Patented Oct. 13, 1914.

I [/VVENTOR.

WITNAiSZ wgaw )4. x W11 THE NORRIS PETERS CO" PHOWUTHQ. WASHINGIDN. D. C

\ UNITED STATES PATENToFFIoE.

WILLIAM r. BENHAM, or Ram sun, iivnIANA.

rnnrmrarion tocn an Specification of Letters latent.

l atented 0a. 13, 1914.

Application filed January 28, 1913. Seria1No.x744,606.

To allevfiomitmay concern:

Be it known that 1, WILLIAM T. BENHAM, a citizen of the United States, residing at Rising Sun, in the county of Ohio and State of Indiana, have invented new and useful Improvements in Permutation-Lock Dials, of which the following is a specification.

My invention relates to the class of locks embodying a rotating dial such as are commonly used on safes. tice universally in vogue among manufacturers of safe locks of this character, so far as I am aware, the dial numbering of the equal fractional units of rotation is from left to right for the entire rotation. As applied to combination looks of the ordinary type, in running the combination to place the tumblers or guards in position topermit the unlocking of the safe, it is necessary in the making the right and left movements of the dial, to keep the passing numbers in mind with absoluteaccuracy in connectibn with changes in the requirements of direction and number of revolutions in easily comprehended and more speedily andcertainly performed.

To this end my invention consists in the combination and use,'in a dial lock of this character, of a rotating dial-platen numbered in successive fractional rotationsboth to right and left of a common starting point which may be designated as zero and repre* sented by the cipher mark ;the total numbering in each direction occupying half a rotation while entire rotations are marked by the coincidence of the zero rim surrounding the dial.

My invention is represented in thedrawing accompanyingand forming part of this specification, bythe figureof a dial plate with radial marks indicating fractional ro- By the common prac-- point with a single gage mark upon the fixed annular tations up to twenty-five in both directions from the same starting point.

Referring now to said drawing, A designates the rotating dial plate; B its surroundingufixed annulus; and a the usual central knob; For greater convenience, a pointer on may be attached to the dial at the zero point,

1 projecting slightlyover the annulus to mark 10 is reached.

with greater certainty of observation the coincidence with the single gage mark Z) upon the annulus B. The marks (:3 upon the dial extend radially slightly inward from the periphery and indicate successive equal movements of rotation right and left from the zero point and each successive fifth mark is somewhat prolonged-'towardthe center of the dial and designated by numbers 5, 10, 15, etc., to 25-this last being at or within the diametrical line from the zero point. In the present illustration I have shown the series of numbers at each side as terminating a trifle short ofthis diameter, leaving a neutral segment between so that each series is entirely independent in its numberingan incidental feature which adds in a slight degree to certainty of manipulation.

The operation of the dial is as followsto take a concrete example as operated by the dial commonlyin use and contrasting it with the operation of the dial herein shown and described:

The,oZcZ.-Turn right 3 times and stop at 20. Turn left twice passing 20 and stop at 30. Turn right once passing 30 and stop at 10. This involves: first, three entire revolutions to the right past zero from the point of beginning (whatever it may happen to be) 'and'continuing on until the 20 mark coincides with the gage mark of the annulus; second, two entire revolutions backward from 20 as a starting and ending point, continuing on until 30 coincides with the gage mark of the annulusythird, one complete revolution tothe right from 30 as a starting and ending polnt, and continuing on until In this, the first operation after the completed entlre revolutions involves a reading of the dial marks backward in succession until 20 is reached; in the second operation this number must be kept in 'mind as the basis of complete rotations and then reading the dial marks forward in succession until a new number30-1s reached,

which in turn displaces the former number-20-and bec0mes,.as in the former case,

a basis for the final complete rotations.

, stinctive.

To operate the same combination by my improvement it is only necessary to remember that all rotations refer to the coincidence of the zero mark on the dial With the gage mark of the annulus; so that whatever be thestarting point, a given number of rotations means simply the passing coincidence of zero and gage marks a given number of times. The zero point being preferably always at the zenith point of the dial and marked in some emphatic manner-as in the present illustration by a pointer,thi s much of the manipulation soon becomes in- Also, that as the dial readings in either direction are always in forward succession of numbers from this common starting point-zorm-and never backv'vard andnever from the previously-reached point in the dial numbering, the matter of the adjustment to. special numbers on the dial is rendered simple and certain. Thus the operation of the same combination, described in terms of my improvement Would be:

The newt-Turn right, pass 0, 3 times, continue to 20 (right hand). Turn left,

pass 0, twice, continue to 20 (left hand). Turn right, pass 0, once, continue to 10 (right hand).

claim as my invention and desire to secure by Letters Patent of the United States:

In a dial lock of the character indicated, the combination of a rotatable dial. plate having its outer circumferential space marked in equal fractional divisions of retation numbered in forward succession in rotations of the latter by coincidence of dial marks with said fixed mark.

in testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

TVILLIAM T. BENHAM. lVitnesses Lnwis M. HosEA, Amen L. TILDESLEY.

, v M 1 copies of this patent may be obtained for true cents each, by addressing the Commissioner of l'atents,

' Washington, I). C." 

